Molding system having a residue cleaning feature and an adjustable mold shut height

ABSTRACT

A method is provided of cleaning of a portion of a mold component, the portion of the mold component including a passage configured, in use, to allow passage of fluid and to prevent passage of melt, the method comprising: entering the mold component into a cleaning configuration, whereby a portion of the passage becomes part of a molding surface; performing a molding cycle to fill in at least the portion of the passage with molding material for incorporation and removal of a residue there from. Also provided is a mold having a first mold half and a second mold half, the halves being movable relative to each other. A mold shut height adjustment apparatus can provide for a change in the mold shut height

RELATED APPLICATIONS

This application is a divisional of U.S. patent application Ser. No.13/756,693 which is a continuation-in-part of PCT patent applicationserial no. PCT/CA2012/050408 filed Jun. 20, 2012, designating inter aliathe United States of America, and which claimed priority from U.S.provisional patent application Ser. No. 61/514,931 filed Aug. 4, 2011,the entire subject contents of both such patent applications beinghereby incorporated by reference in their entirety herein as if fullyset forth herein.

FIELD OF THE INVENTION

The present invention generally relates to, but is not limited to,molding systems, and more specifically the present invention relates to,but is not limited to, molding systems having a residue cleaning featureand to molding systems with an adjustable mold shut height and/oradjustable neck ring configuration.

BACKGROUND OF THE INVENTION

Molding is a process by virtue of which a molded article can be formedfrom molding material by using a molding system. Various molded articlescan be formed by using the molding process, such as an injection moldingprocess. One example of a molded article that can be formed, forexample, from Polyethylene Teraphalate (PET) material is a preform thatis capable of being subsequently blown into a beverage container, suchas, a bottle and the like.

As an illustration, injection molding of PET material involves heatingthe molding material (ex. PET pellets, etc.) to a homogeneous moltenstate and injecting, under pressure, the so-melted PET material into amolding cavity defined, at least in part, by a female cavity piece and amale core piece mounted respectively on a cavity plate and a core plateof the mold. The cavity plate and the core plate are urged together andare held together by clamp force, the clamp force being sufficientenough to keep the cavity and the core pieces together against thepressure of the injected PET material. The molding cavity has a shapethat substantially corresponds to a final cold-state shape of the moldedarticle to be molded. The so-injected PET material is then cooled to atemperature sufficient to enable ejection of the so-formed moldedarticle from the mold. When cooled, the molded article shrinks inside ofthe molding cavity and, as such, when the cavity and core plates areurged apart, the molded article tends to remain associated with the corepiece. Accordingly, by urging the core plate away from the cavity plate,the molded article can be demolded, i.e. ejected off of the core piece.Ejection structures are known to assist in removing the molded articlesfrom the core halves. Examples of the ejection structures includestripper plates, ejector pins, etc.

When dealing with molding a preform that is capable of being blown intoa beverage container, one consideration that needs to be addressed isforming a so-called “neck portion”.

Typically and as an example, the neck portion includes (i) threads (orother suitable structure) for accepting and retaining a closure assembly(ex. a bottle cap), and (ii) an anti-pilferage assembly configured tocooperate, for example, with the closure assembly to indicate whetherthe end product (i.e. the beverage container that has been filled with abeverage and shipped to a store) has been tampered with in any way. Theneck portion may comprise other additional elements used for variouspurposes, for example, to cooperate with parts of the molding system(ex. a support ledge, etc.). As is appreciated in the art, the neckportion can not be easily formed by using the cavity and core halves.Traditionally, split mold inserts (sometimes referred to by thoseskilled in the art as “neck rings”) have been used to form the neckportion.

With reference to FIG. 1, a section along a portion of an injection mold50 illustrates a portion of typical molding insert stack assembly 60that is arranged within a molding system (not depicted). The descriptionof FIG. 1 that will be presented herein below will be greatlysimplified, as it is expected that one skilled in the art willappreciate general configuration of other components of the injectionmold 50 that will not be discussed in the following description.

The molding insert stack assembly 60 includes a neck ring insert pair 52that together with a mold cavity insert 54, a gate insert (not shown)and a core insert 61 define a molding cavity (not separately numbered)where molding material can be injected to form a molded article, such asa preform 63. In order to facilitate forming of the neck portion of thepreform 63 and subsequent removal of the preform 63, the neck ringinsert pair 52 comprises a pair of complementary neck ring inserts thatare mounted on adjacent slides of a slide pair 68. The slide pair 68 isslidably mounted on a top surface of a stripper plate 66. As commonlyknown, and as, for example, generally described in U.S. Pat. No.6,799,962 to Mai et al (granted on Oct. 5, 2004), the stripper plate 66is configured to be movable relative to a cavity plate assembly 74 and acore plate assembly (not depicted), when the mold is arranged in an openconfiguration, whereby the slide pair 68, and the complementary neckring insert pair 52 mounted thereon, can be laterally driven, via a camarrangement or some other means (not shown), for the release of themolded article from the molding cavity.

A typical neck ring insert has a body that includes a pair of projectingportions 70 that extend from a top and a bottom face of a flange portion72 (i.e. a top projecting portion and a bottom projecting portion).Typically, the bottom face of the flange portion 72 abuts, in use, a topsurface of the slide pair 68. Even though not depicted in FIG. 1, oneskilled in the art will appreciate that the neck ring insert pair 52cooperates with suitable fasteners for connecting to a respective one ofthe slide pair 68. In use, during certain portions of a molding cycle,the top projecting portion cooperates with a female receptacle disposedon the cavity plate assembly 74.

FIG. 2 depicts an example of a prior art implementation of a neck ring200 of the neck ring insert pair 52. More specifically, FIG. 2 depicts afront planar view of the neck ring 200. The neck ring 200 comprises amolding surface 202 for forming, in use, various portions of the neckfinish of the preform and a mating surface 204 for abutting, in use,another one of the neck ring 200. The neck ring 200 further includes aventing structure 206. The venting structure 206 comprises (i) an airvent groove 208 for collecting and venting, in use, excess air from themolding cavity as it is being filled with the molding material and (ii)an air collector groove 210 in fluid communication with the air ventgroove 208 for providing an evacuation path for the air to be ventedfrom the vent groove 208.

U.S. Pat. No. 7,939,009 issued to Balboni, et al. on May 10, 2011discloses a preform that is formed by an upper neck which maintainsunchanged its form in the final object and a hollow body, joined to theneck. The method foresees the insertion, within a matrix cavity, of ametered body of polymeric material whose mass is metered according to areference value, and the subsequent pressure insertion of a punch withinthe matrix cavity until it closes the mold's molding chamber, the punchconferring the shape to the inner surface of the preform and the matrixhaving an inner surface which confers the shape to the outer surface ofthe preform. According to the invention, in the molding of the preform,the error of the mass of the metered body with respect to the referencevalue is distributed in the hollow body, which undergoes a subsequenthot deformation until it achieves the final shape. In the mold, thematrix comprises at least one deformable wall (31) whose inner surfacedefines at least part of the inner surface of the matrix part intendedto give form to the hollow body of the preform, said deformable wall(31) having, at least in part, a relatively thin thickness which permitsit to be elastically deformed under the pressure of the polymericmaterial in the final preform molding step, thereby varying thethickness of the hollow body.

U.S. Pat. No. 7,128,865 issued to Martin on Oct. 31, 2006 discloses aninjection molding method and apparatus for ejecting a molded plasticpreform from a mold. A first lifting structure and/or step is configuredto have an inner surface with an area for sealing and aligning with acomplementary surface on a core, and to have an upper surface with anarea for sealing and aligning with a complementary surface on a secondlifting structure, said upper surface of said first lifting structurebeing configured to lift a molded plastic preform from the injectionmold in a lifting direction for a first period of time, the lowerportion of the molded plastic preform lying in a plane substantiallyperpendicular to the lifting direction. A second lifting structureand/or step is configured to have an inner surface configured to lift anouter surface of the molded plastic preform from the injection mold inthe lifting direction for a second period of time, the outer surface ofthe molded plastic preform including structure lying in a planesubstantially parallel with the lifting direction. Since the moldedplastic preform is lifted by its end, the preform does not have to besolidified at its interior, thus allowing earlier removal of the preformfrom the mold, reducing cycle time.

U.S. Pat. No. 7,481,642 issued to Niewels on Jan. 27, 2009 discloses amethod and apparatus for controlling a vent gap in a mold for aninjection molding machine, which include an active material insertconfigured to be regulate the degree of opening of the vent gap. Theactive material insert is configured to be actuated in response tosignals from a controller, so as to selectively block the opening of thevent gap during the molding process. Wiring structure is coupled to theactive material insert, and is configured to carry the actuationsignals. Melt flow sensors may also be provided to aid in regulating thevent gap, and may be connected to the controller in order to providereal-time closed loop control over the operation of the vent gap.Preferably, the methods and apparatus are used as part of a system forcontrolling the flow of melt within a mold cavity.

SUMMARY OF THE INVENTION

According to a first broad aspect of the present invention, there isprovided a method of cleaning of a portion of a mold component, theportion of the mold component including a passage configured, in use, toallow passage of fluid (such as air) and to prevent passage of melt, themethod comprising: entering the mold component into a cleaningconfiguration, whereby a portion of the passage becomes part of amolding surface; performing a molding cycle to fill in at least theportion of the passage with molding material for incorporation andremoval of a residue therefrom.

According to a second broad aspect of the present invention, there isprovided a mold component configured to be actuated between: a firstconfiguration in which the mold component comprises a passage thatallows passage of fluid (such as air) and prevents passage of the melt;and a second configuration in which the passage is actuated such as tobecome part of a molding surface.

According to a third broad aspect of the present invention, there isprovided a neck ring for defining at least a portion of a neck portionof a preform, the neck ring comprising: a molding surface defining aportion of a molding cavity for defining the at least a portion of theneck portion of the preform; a venting structure for evacuating thefluid, in use, from the molding cavity, the venting structure including:a primary vent groove; a secondary vent groove; a pocket groove in fluidcommunication with both the primary vent groove and the secondary ventgroove.

According to a fourth broad aspect of the present invention, there isprovided a method of operating a mold comprising: maintaining a neckring in a standard molding configuration and executing at least onemolding cycle; actuating the neck ring into a vent cleaningconfiguration and executing at least one molding cycle in the ventcleaning configuration to remove residue from at least a primary ventgroove of the neck ring.

According to another broad aspect of the present invention, there isprovided a distance augmenting structure for use in an injection moldingmachine between a first machine component and a second machinecomponent, the distance augmenting structure comprising: a baseoperatively attachable, in use, to one of the first machine componentand a second machine component; an actuator, a distance adjustmentinsert operatively coupled to the actuator, the actuator beingconfigured to translate the distance adjustment insert between anoutbound position in which position the distance adjustment insert ispositioned away from the first machine component and the second machinecomponent; and an in-bound position, in which the distance adjustmentinsert is positioned between the first machine component and the secondmachine component, in which inbound position the distance adjustmentinsert is configured to increase distance between the first machinecomponent and the second machine component.

According to yet another broad aspect of the present invention, there isprovided a method of operating a mold, the mold comprising a first moldhalf and a second mold half, the first mold half and the second moldhalf defining a passage configured, in use, to allow passage of fluidand to prevent passage of melt, the method comprising: maintaining themold in a standard molding configuration and executing at least onemolding cycle; actuating the first mold half and the second mold halfinto a cleaning configuration and executing at least one molding cyclein the cleaning configuration to remove residue from at least a portionof the passage.

According to another broad aspect of the invention there is provided aninjection mold comprising a first mold half and a second mold half. Thefirst and second mold halves are supported and movable relative to eachother, and the first and second mold halves have a mold shut height whensaid mold is an operational configuration. The mold also comprise a moldshut height adjustment apparatus operable to provide for a change in themold shut height.

According to another broad aspect of the invention there is provided amethod of operating an injection mold comprising: (i) operating the moldin a first operational configuration; (ii) varying a mold shut height ofthe mold; and operating the mold in a second operational configuration.

According to another broad aspect of the invention there is provided amold height adjustment apparatus for an injection mold. The injectionmold comprises a first mold half and a second mold half, the first andsecond mold halves being supported and movable relative to each otherand the first and second mold halves having a mold shut height when saidmold is an operational configuration. The mold shut height adjustmentapparatus is operable to provide for a change in the mold shut height.

These and other aspects and features of non-limiting embodiments of thepresent invention will now become apparent to those skilled in the artupon review of the following description of specific non-limitingembodiments of the invention in conjunction with the accompanyingdrawings.

DESCRIPTION OF THE DRAWINGS

A better understanding of the embodiments of the present invention(including alternatives and/or variations thereof) may be obtained withreference to the detailed description of the non-limiting embodimentsalong with the following drawings, in which:

FIG. 1 depicts a cross-section along an operational axis of a moldingstack implemented in accordance with known techniques;

FIG. 2 is a front planar view of a neck ring of the molding stack ofFIG. 1, implemented in accordance with known techniques;

FIGS. 3A-3F depict a schematic top view of a neck ring implementingembodiments of the present invention, the neck ring in a standardmolding configuration and in progression through vent cleaningconfigurations;

FIG. 4 depicts a flow chart of a method for molding and vent cleaningimplemented in accordance with non-limiting embodiments of the presentinvention;

FIG. 5 depicts a front view of (i) a portion of a molding stack 502 thatincludes a neck ring 504 and a lock ring 506, the neck ring 504 beingimplemented in accordance with non-limiting embodiments of the presentinvention and being shown in the standard molding configuration; and(ii) a portion of a molding stack 508 that includes the neck ring 504and the lock ring 506, the neck ring 504 being implemented in accordancewith non-limiting embodiments of the present invention and being shownin the vent cleaning configuration;

FIG. 6 depicts a perspective view of the entirety of the neck ring 300implemented in accordance with non-limiting embodiments of the presentinvention;

FIG. 7 depicts a perspective view of a portion of the neck ring 300 ofFIG. 6.

FIGS. 8A-8C depict a top view of a portion of an injection moldingmachine 800, implemented in accordance with embodiments of the presentinvention;

FIG. 9 depicts a section view of a mold in accordance with anotherembodiment of the present invention, the mold being in a standardmolding configuration;

FIG. 10 depicts a section view of the mold of FIG. 9 in a cleaningconfiguration;

FIG. 11 depicts a section view of another mold in a standard moldingconfiguration;

FIG. 12 depicts a section view of the mold of FIG. 11 in a cleaningconfiguration;

FIG. 13 depicts a section view of the mold of FIG. 11 in an alternatecleaning configuration;

FIG. 14 is a cross-sectional view through part of a mold;

FIG. 14A is an enlarged view of the representative portion that ismarked as 14A in FIG. 14 including one representative mold stack;

FIG. 15 is an isometric view of a core plate of the mold of FIG. 14;

FIG. 16A is a front elevation view of the core plate of FIG. 15;

FIGS. 16B and 16C are cross-sectional views of the core plate of FIG.16A, along sections 16B-16B and 16C-16C, respectively;

FIG. 16D is an enlarged view of the cross-section shown in FIG. 16C;

FIG. 16E is an enlarged view of the cross-section shown in FIG. 16B;

FIG. 16F is an enlarged view of the portion 16F in FIG. 16E, with afurther enlarged portion thereof;

FIG. 16G is an enlarged view of the portion 16G in FIG. 16E;

FIG. 16H is a view of part of the portion 16F in FIG. 16E shown in aretracted position, with a portion of a stripper plate of the mold;

FIG. 16I is a view of the part of FIG. 16H but shown in an extendedposition, with a portion of a stripper plate of the mold;

FIG. 17 is an isometric view of a sub-assembly of the injection moldpart of FIG. 14;

FIG. 18 is an isometric view of another sub-assembly of the injectionmold part of FIG. 14;

FIG. 19 is an isometric view of another sub-assembly of the mold part ofFIG. 14;

FIG. 20A is an isometric view of another sub-assembly of the mold partof FIG. 14

FIGS. 20B-20C are enlarged views of portions marked 20B, 20C,respectively, of the sub-assembly of FIG. 20A;

FIG. 20D is a cross-sectional view at section 20D-20D in FIG. 16A;

FIG. 20E is an enlarged view of portion marked 20E in FIG. 20D;

FIG. 20F is a top plan view of the portion marked 20B in FIG. 20A in oneoperational position;

FIG. 20G is a top plan view of the portion in FIG. 20F but in anotheroperational position;

FIG. 21A is a front elevation view of a stripper plate of the mold ofFIG. 14, mounted on the core plate of FIG. 15;

FIG. 21B is a cross-sectional view of the stripper plate and core plateof FIG. 21A at section 21B-21B in FIG. 21A.

FIG. 21C is an enlarged view of the cross-section shown in FIG. 21B;

FIG. 21D is an enlarged view of the portion marked 21D in FIG. 21C;

FIG. 22 is an isometric view of a cavity plate of the mold part of FIG.14;

FIG. 23A is a front elevation view of the cavity plate of FIG. 22;

FIG. 23B is a cross-sectional view of the cavity plate of FIG. 23A atsection 23B-23B in FIG. 23A;

FIG. 23C is an enlarged view of the cross-section shown in FIG. 23B;

FIG. 24 is an enlarged view of the portion marked 24 in FIG. 23C;

FIG. 25 is an exploded view of a part shown in FIG. 24;

FIG. 26A is enlarged view of the portion marked 26 in FIG. 23C in oneoperational position;

FIG. 26B is an enlarged view of the portion marked 26 shown in FIG. 23Cbut in another operational position;

FIG. 27 is a cross-sectional view through part of the mold part of FIG.14, with the injection mold open; and

FIG. 28 is a cross-sectional view through part of the mold part of FIG.14 with the injection mold in an alternate configuration.

The drawings are not necessarily to scale and are may be illustrated byphantom lines, diagrammatic representations and fragmentary views. Incertain instances, details that are not necessary for an understandingof the non-limiting embodiments or that render other details difficultto perceive may have been omitted.

DETAILED DESCRIPTION OF EMBODIMENTS

With reference to FIGS. 6 and 7, there is depicted a perspective view ofa neck ring 300, the neck ring 300 being suitable for implementation ofembodiments of the present invention. FIG. 6 depicts a perspective viewof the entirety of the neck ring 300, while FIG. 7 depicts a perspectiveview of a portion of the neck ring 300. The neck ring 300 comprises oftwo halves thereof, the halves of the neck ring 300 definingtherebetween a shut off face 700.

Further description will make continued reference to FIGS. 6 and 7, andwill make reference to FIGS. 3A-3F, which depict the neck rings 300 invarious stages of the molding and vent cleaning cycles, as will bedescribed in greater detail herein below.

In particular, FIG. 3A depicts a schematic representation of the topview of the neck ring 300 in a “standard molding configuration”, theneck ring 300 being implemented in accordance with non-limitingembodiments of the present invention. FIG. 3B depicts a portion of theneck ring 300 of FIG. 3A in greater detail. The neck ring depicted inFIG. 3A comprises a first body portion 302 and a second body portion304. In the embodiment being depicted herein, the first body portion 302and the second body portion 304 are embodied in a first neck ring halfand a second neck ring half. Defined between the first body portion 302and the second body portion 304 is the aforementioned shut off face 700.Within the shut off face 700, there is provided a venting structure 306.The general purpose of the venting structure 306, much akin to the priorart implementation of the venting structure, is for collecting andventing, in use, excess fluid (such as air) from the molding cavity andproviding an evacuation path for such vented air. Within theseembodiments, the venting structure 306 comprises a primary vent area 308and a secondary vent area 310. It is noted that “vent area” is alsoreferred to by some skilled in the art as “vent grooves”, but it is notso limited. In the depicted embodiments, the primary vent area 308 andthe secondary vent area 310 are implemented as cooperating (or tandem)structures. As an example only and by no means as a limitation, theprimary vent area 308 and the secondary vent area 310 are implemented asparallel to each other, but other spatial relationship can beimplemented in alternative embodiments of the present invention.

There is also defined a pocket groove 312, located in-between and influid communication with the primary vent area 308 and the secondaryvent area 310. In the specific example depicted herein, the pocketgroove 312 is generally triangular in shape. However, this needs not beso in every embodiments of the present invention and the shape of thepocket groove 312 can be implemented differently. In other words, thepocket groove 312 can be implemented in a different form factor. Thegeneral purpose for the pocket groove 312 is to provide a reservoir forrapid evacuation of fluid (such as air) from the molding cavity throughthe primary vent area 308.

Recalling that the neck ring 300 of FIG. 3A is depicted in the standardmolding configuration, the primary vent area 308 is dimensioned for (i)allowing the passage of the evacuated fluid (such as air) from themolding cavity into the pocket groove 312 and (ii) not allowing anysubstantial amount of the molding material for passing therethrough. Ina particular example of an implementation, the width of the primary ventarea 308 can be between 0.03 and 0.04 mm, in case of the molding of PETpreforms.

At the same time, the dimension of the secondary vent area 310 is suchthat it prevents the passage of any substantial amount of the moldingmaterial for passing therethrough. In the specific examples, the wallsof the shut off face 700 defining the secondary vent area 310 can toucheach other in order to prevent the passage of evacuated fluid (such asair) and to prevent the flow of molding material, in this standardmolding configuration or, alternatively, they can define a gap therebetween, which gap allows for the flow of evacuated fluid (such as air)but prevents passage of the molding material.

Within the configuration of FIG. 3D and as is more clearly visible inFIG. 3F, there is also provided an apex point 334. The apex point 334 issized such as to provide the path for evacuated fluid (such as air)towards the secondary vent area 310 while preventing the flow of anysubstantial amount of molding material there through (in other words,the apex point 334 is the beginning portion of the secondary vent area310, while the remainder of the secondary vent area 310 starts to act asa reservoir for the escaped air). It is noted that in some embodimentsof the present invention, in the vent cleaning configuration, the apexpoint 334 provides a clearance of approximately 0.03 to 0.04 mm.

To complete the description of FIG. 3A and FIG. 3B, there are alsodepicted a molding surface 322 that cooperates with a portion of a core(not depicted), which define therebetween a portion of a molding cavity(not separately numbered) into which molding material flows to define amolded article.

With reference to FIG. 3C, after a certain number of molding cycles,there tends to accumulate some residue 330 along at least a portion ofthe primary venting groove 308 (such as material dust, contaminants orother undesirable particles or the like).

With reference to FIG. 3D, there is depicted a schematic representationof the top view of the neck ring 300 in a “vent cleaning configuration”,the neck ring 300 being implemented in accordance with embodiments ofthe present invention. In embodiments of the present invention, thisconfiguration can be thought of as “breathing mode” or “controlled flashmolding” configuration. Accordingly and as means of an example, thisvent cleaning configuration can be entered into by means of decreasingclamp pressure (by means of software adjustment, for example), comparedto the standard molding configuration, depicted in FIG. 3A, for example.

In an example embodiment, it is contemplated that the clamp tonnage canbe lowered by approximately ten to fifteen percent below the minimuminjection pressure for the same mold. As an example, in a typical72-cavity mold used for a water application with split at support ledgewith diameter 34 mm, an operational tonnage (i.e. one applied inconfiguration of FIG. 3A) can be around 290 tons, with the minimumprocess tonnage of 230 tons, while the tonnage used for entering thevent cleaning configuration can be about 200 tons.

Recalling that the neck ring 300 of FIG. 3D is depicted in the ventcleaning configuration (or, more specifically in a configuration at thebeginning of the vent cleaning process in accordance with embodiments ofthe present invention), the primary vent area 308 is dimensioned forallowing passage of the molding material therethrough. In a sense, inthe vent cleaning configuration, the primary vent area 308 becomes partof the molding surface and allowing the molding material 326 to fill inthe primary vent area 308 in the vent cleaning configuration. At thesame time, the secondary vent area 310 is dimensioned for (i) allowanceof the passage of the evacuated fluid (such as air) from the primaryvent area 308 and (ii) not allowing any substantial amount of themolding material for passing therethrough. In a sense, within the ventcleaning configuration, the secondary vent area 310 “becomes” orexecutes the function of the primary vent area 308 as depicted in FIG.3A (i.e. in the standard molding configuration).

With reference to FIG. 3E, the commencement of the vent cleaning phaseis depicted, whereby molding material 326 starts to fill in the moldingcavity defined between the neck ring 300 and the core 314. Eventually,the molding material 326 starts to fill the primary vent area 308,including or incorporating the residue 330. With reference to FIG. 3F,the molding material 326 continues to travel through the primary ventarea 308, at this point fully incorporating the residue 330. As such, atthe end of the vent cleaning cycle, the molding material 326 has fullyfilled the primary vent area 308 and has fully incorporated the residue330. At this point, the molding material 326 allowed to cool down, in astandard manner.

After a sufficient period of time to allow the molding material 326 tocool down sufficiently to enable removal thereof from the neck ring 300the molded article is ready for removal from the neck ring 300. As canbe appreciated, the resultant molded article includes a molded appendix360, which generally corresponds in shape to the shape of the primaryvent area 308 incorporating the residue 330. As such, ejection of themolded article, including the molded appendix 360, results ineffectively removing it from the neck ring 300.

In some embodiments of the present invention, the inner walls of eitheror both of the primary vent area 308 and the secondary vent area 310 canbe coated with a coating to reduce sticking of the molding material 326thereto.

Given the architecture described above with reference to FIGS. 3A-3F, itis possible to execute a method of molding and vent cleaning inaccordance with embodiments of the present invention. Generallyspeaking, embodiments of the present invention allow to actuate the neckring 300 between the standard molding configuration (in which a moldedarticle, such as preform suitable for subsequent blow molding can bemolded) and the vent cleaning configuration (in which residue 330 can beremoved from the primary vent area 308). Furthermore, according toembodiments of the present invention, the controlled flash condition isused to clean the vent areas and to remove the undesired particlestherefrom. More specifically, in the vent cleaning configuration, themelt is used to fill in the primary vent area 308 for incorporation andremoval of the residue 330.

More specifically, a method 400 can be executed by a controller (notdepicted) of a molding machine (not depicted), both can be executed inaccordance with known prior art techniques. The molding machineincluding the neck ring(s) 300 in accordance with the number of moldingcavities desirable.

Step 402

At step 402, the neck ring 300 is maintained in the standard moldingconfiguration, as that of FIG. 3A. The neck ring 300 is maintained inthe standard molding configuration by means, for example, of applicationof standard clamp force (such as a force that is sufficient to withstandmolding pressure of the molding material and to maintain the mold in aclosed configuration).

A molded article is molded. The molding cycle can be repeated until themethod progresses to step 404, as will be described momentarily.

Step 404

At step 404, the configuration of the neck ring 300 is controlled intothe vent cleaning configuration. Step 404 can be executed when it isdetermined that vent cleaning is required. This can be executed at apre-determined interval, for example, every month or every n-number ofmolding cycles (such as fifty thousand, eighty thousand or hundredthousand molding cycles). Alternatively, this can be executed when thequality of the molded article falls under a pre-determined threshold.Alternatively, this can be executed in accordance with preventativemaintenance schedule for a given operator of the molding machine (notdepicted).

Step 404, as has been previously described, can be executed by means ofdecreasing clamp pressure, compared to the standard moldingconfiguration and executing an injection cycle. In some embodiments ofthe present invention, step 404 can be repeated several times. It isnoted that the molded articles molded during the vent cleaning operationare scrapped, as they include particles of the residue 330.

Once the vent cleaning operation is executed, the method 400 can returnto execution of step 402, i.e. to the standard molding configuration.

Accordingly, it can be said that the method of vent cleaning inaccordance with embodiments of the present invention includes, at acertain number of molding cycles where residue 330 has accumulates ontowalls of the primary vent area 308, executing a vent cleaning operationby means of:

-   -   entering the neck ring into the vent cleaning configuration        (whereby the primary vent area 308 becomes part of the molding        surface for allowing melt therein and the secondary vent area        310 becomes the primary venting structure);    -   executing a molding cycle to fill in the primary vent area 308        with molding material for incorporation and removal of the        residue 330 therefrom.

Generally speaking and considering the neck ring 300 as an example ofimplementation of a method for vent cleaning in a molding structurehaving a venting structure 306, one can say that the method of ventcleaning comprises:

-   -   entering the mold structure housing the venting structure 306        into a vent cleaning configuration;    -   performing a molding cycle to fill in at least a portion of the        venting structure 306 with molding material for incorporation        and removal of a residue 330 therefrom;    -   while executing said performing, allowing for the fluid (such as        air) to be evacuated from the at least a portion of the venting        structure 306 through a secondary vent area 310.

It should be expressly understood that embodiments of the presentinvention described above with reference to the controllable primary andsecondary vent areas are used just as examples of cleaning split linesurfaces (such as the shut off face 700). It should be furtherunderstood that embodiments of the present invention can be used toclean other types of the split lines present in the mold.

As such, embodiments described above are implemented in a “neck-to-neck”vent configuration. It is also possible to execute the embodiments ofthe present invention in a “neck-to-lock” configuration. Example of suchnon-limiting embodiments is depicted with Reference to FIG. 5.

FIG. 5 depicts a front view of (i) a portion of a molding stack 502 thatincludes a neck ring 504 and a lock ring 506, the neck ring 504 beingimplemented in accordance with non-limiting embodiments of the presentinvention and being shown in the standard molding configuration; and(ii) a portion of a molding stack 508 that includes the neck ring 504and the lock ring 506, the neck ring 504 being implemented in accordancewith non-limiting embodiments of the present invention and being shownin the vent cleaning configuration.

According to embodiments of the present invention, there is provided aprimary vent area 512, a secondary vent area 516 and a pocket groove514. Within the standard molding configuration of the molding stack 502,the primary venting groove and the secondary vent area 516 can beimplemented as having the width of 0.03 mm and the pocket groove 514 canbe implemented with the width of 0.05 mm

Generally speaking, in the standard molding configuration, the primaryvent area 512 is dimensioned for (i) allowance of the passage of theevacuated fluid (such as air) from the molding cavity into pocket groove514 and (ii) not allowing any substantial amount of the molding materialfor passing therethrough. At the same time, the dimension of thesecondary vent area 516 is such that it also prevents the passage of anysubstantial amount of the molding material for passing therethrough.

In the vent cleaning configuration of the molding stack 508, the primaryvent area 512 can be implemented as having the width of 0.28 mm, and thesecondary vent area 516 remains at 0.05 mm More generally, the primaryvent area 512 is dimensioned for allowing passage of the moldingmaterial therethrough. In a sense, in the vent cleaning configuration,the primary vent area 512 becomes part of the molding surface. At thesame time, the secondary vent area 516 is dimensioned for (i) allowanceof the passage of the evacuated fluid (such as air) from the primaryvent area 308. In a sense, within the vent cleaning configuration, thesecondary vent area 516 “becomes” or implements the function of theprimary vent area 512 in the standard molding configuration, while thepocket groove 514 is configured for the rapid evacuation of fluid (suchas air) from the molding cavity through the primary vent area 512.

This vent cleaning configuration can be entered into by means ofdecreasing clamp pressure (by means of software adjustment, forexample), compared to the standard molding configuration. In an exampleembodiment, it is contemplated that the clamp tonnage can be lowered byapproximately ten to fifteen percent below than the minimum injectionpressure for the same mold. As an example, in a typical 72-cavity moldused for a water application, an operational tonnage can be around 290tons, with the minimum process tonnage of 230 tons, while the tonnageused for entering the vent cleaning configuration can be about 200 tons.

A technical effect of embodiments of the present invention includesability to execute vent cleaning operation without substantialinterruption to the operation of the injection molding machine. Anothertechnical effect of embodiments of the present invention includesability to execute the injection molding machine without the need tostop the injection molding machine and without the need for the purgingoperation of the injection screw. Another technical effect ofembodiments of the present invention includes ability to execute a ventcleaning operation that does take comparatively less time vis-à-visexisting solutions for vent cleaning. Another technical effect ofembodiments of the present invention includes the ability to execute thevent cleaning operation without the uncontrolled dust transferassociated with the prior art solutions (such as blowing air, forexample). It should be expressly understood that not each everytechnical effect needs to be present in each and every embodiment of thepresent invention.

It should be noted that the above described embodiment of the ventcleaning is just one example of a method of cleaning of a passage thatis configured, in use, to allow for the passage of fluid (such as airand the like) and to prevent passage of the melt. Embodiments of thepresent invention allow for entering such passage into a cleaningconfiguration and to allow the passage to become part of the moldingsurface. Effectively, embodiments of the present invention contemplateflooding at least a portion of the passage with melt to remove residue330 therefrom. It is noted that at least a portion of such passage thatis wetted in use by the fluid (and therefore tends to accumulate residue330) can be cleaned by using embodiments of the present invention. Otherexamples of such the passage can include TSS vent grooves, core/lockring vent grooves, inner and outer core vent grooves in closure moldsand the like.

Accordingly, it can be said that the method of cleaning of a passagethat during a molding configuration (i.e. in use) allows the passage offluid and prevents passage of melt, the passage associated with a moldcomponent (an example of which is being the above-described neck ring300, but not so limited) in accordance with embodiments of the presentinvention includes, at a certain number of molding cycles where residue330 has accumulates onto at least a portion of the passage (such as aportion of the primary vent area 308 and the like, but not so limited),executing a cleaning operation by means of:

-   -   entering the mold component into a cleaning configuration,        whereby a portion of the passage associated with the mold        component that accumulates residue becomes part of the molding        surface;    -   executing a molding cycle to fill in the portion of the passage        with molding material for incorporation and removal of the        residue 330 therefrom.

The method further includes, in some embodiments thereof, controlling amelt front of the melt entering the passage in the cleaningconfiguration. In some embodiments, as is the case in the above neckring 300 embodiment, the control of a predefined point for the meltfront stop in the vent cleaning configuration is executed by means of aphysical stop, such as the above-described apex point 334. In otherembodiments of the present invention, the predefined point for the meltfront can be executed as a thermal implementation (i.e. by controllingthe temperature or rate of a cooling fluid around the predefined pointfor the melt front stop to effectively freeze off the melt). Otherembodiments and executions for the predefined point for the melt frontstop are possible. Therefore, it can be said that in the cleaningconfiguration the melt flooding of the passage is executed in a“controlled manner” or, in other words, by controlling the predefinedpoint for the melt front stop.

In some embodiments of the present invention, it may be beneficial whileexecuting the molding cycle during the cleaning operation, to increasepressure between molding material and the residue 330. In the aboveexample of the neck ring 300, the increased pressure between the moldingmaterial and the residue 330 is created by: (i) means of increasing theprimary vent area 308 (to transform it into the molding surface) and(ii) creating the secondary vent area 310 with the apex point 334, whichcreate a stop point for the material, thus increasing the pressurebetween the molding material and the residue 330.

Another alternative to increase the pressure between the moldingmaterial and the residue 330 would to create a smaller gap, or in otherwords, when entering the vent cleaning state, increasing the width ofthe primary vent area 308 by a smaller distance, this increasing thepressure between the molding material and the residue 330. Yet in otherembodiments, it is conceivable to increase the pressure between themolding material and the residue 330 by introducing a counter-flow of amedium.

It should be noted that even though description above has used anexample of decreased clamp tonnage to enter into the vent cleaningconfiguration, other implementations are possible. An example of such analternative configuration is depicted with reference to FIGS. 8A-8C.FIGS. 8A-8C depict a top view of a portion of an injection moldingmachine 800, implemented in accordance with embodiments of the presentinvention. The injection molding machine 800 incorporates certainstructures known to those of skill in the art, which structures will notbe described here at any length. Description will follows will focus onspecific modifications implemented in accordance with embodiments of thepresent invention

The injection molding machine 800 comprises inter alia a first mold half802, a second mold half 804, a stripper plate assembly 806, all of whichcan be implemented in accordance with known techniques. According toembodiments of the present invention, there is provided a first distanceaugmenting structure 810 and a second distance augmenting structure 812,which can be implemented substantially similar and, as such, just onewill be described in greater details.

It is noted that the first distance augmenting structure 810 and thesecond distance augmenting structure 812 are operatively positionedbetween respective machine components. The first distance augmentingstructure 810 is operatively positioned between the first mold half 802and the stripper plate assembly 806, while the second distanceaugmenting structure 812 is operatively positioned between the stripperplate assembly 806 and the second mold half 804.

The first distance augmenting structure 810 comprises a base 814operatively attachable to a side of the injection molding machine 800and, more specifically, to the side of the first mold half 802. Thefirst distance augmenting structure 810 further comprises an actuator816, which in this example is implemented as a hydraulic actuator.However, other implementations for the actuator are possible, such as aservo motor or the like. There is also provided a distance adjustmentinsert 818. The distance adjustment insert 818 can be implemented as apiece of sheet metal or the like. The actuator 816 is operable toactuate the distance adjustment insert 818 between an outbound position(FIG. 8A) and an in-bound position (FIGS. 8B and 8C). In the outboundposition, the first mold half 802, the second mold half 804 and thestripper plate assembly 806 will close into the standard moldingconfiguration.

In the in-bound position, as is depicted in FIG. 8C, the first mold half802, the second mold half 804 and the stripper plate assembly 806 willclose into a cleaning configuration with a pre-defined gap therebetween.The pre-defined gap being controlled by the width of the distanceadjustment insert 818. In other words, in-bound position the distanceadjustment insert 818 is positioned between the first machine componentand the second machine component, in which inbound position the distanceadjustment insert 818 is configured to increase distance between thefirst machine component and the second machine component.

It should be expressly understood that the neck ring 300 described aboveis just but one example of embodiments of the present invention forexecuting a method of cleaning of a mold component from the residue 330.With reference to FIG. 9, there is depicted another embodiment of a moldcomponent that can be used for implementing embodiments of the presentinvention. FIG. 9 depicts a section view of a mold 900. The mold 900includes a mold component 902, which in this case is implemented as afirst mold half 904 and a second mold half 906. The first mold half 904and the second mold half 906 define therebetween a molding cavity 908(defined by respective female and male members of the first mold half904 and the second mold half 906). The mold 900 further includes apassage that, in use (i.e. during standard molding operation) allows forthe passage of fluid out of the molding cavity 908 and prevents passageof melt, the passage being depicted in FIG. 9 at 910. The passage 910 isimplemented as a vent area or a “primary vent area’. There is alsoprovided a first passage control member 912, which first passage controlmember 912 is actuatable between a first configuration (where thepassage 910 allows for the passage of fluid and prevents passage of themelt, as depicted in FIG. 9 in which the mold 900 is shown in a standardmolding operation) and a second configuration, in which the passage 910becomes part of the molding surface (depicted in FIG. 10, which depictsthe mold 900 in a cleaning configuration). There is also provided aventing passage 911 in fluid communication with the passage 910 forventing the fluid therefrom.

With continued reference to FIG. 9 and FIG. 10, the mold 900 alsoincludes a second passage control member 914, which is shown in aretracted configuration in FIG. 9 and in an extended configuration inFIG. 10. In the retracted configuration, the second passage controlmember 914 un-obstructs the venting passage 911. In the extendedconfiguration, the second passage control member 914 turns a portion ofthe venting passage 911 into the passage that allows passage of thefluid but not passage of the melt. Effectively, turning a portion of theventing passage 911 into a secondary vent area (as shown in FIG. 10).Optionally or additionally, there is provided a third passage controlmember 916, which can also be controlled similarly to the second passagecontrol member 914 to either provide a venting passage or completelyshut off the passage. In a sense, the second passage control member 914and/or the third passage control member 916 can act to provide thepre-defined point for the melt front stop, as has been previouslydescribed.

The first passage control member 912 and/or second passage controlmember 914 and/or the third passage control member 916 can be actuatedby any suitable means, such as hydraulic actuator, electric actuator andthe like. In a specific embodiment, the actuator can be implemented as apiezzo-electric actuator, similar to the one disclosed in the co-ownedU.S. Pat. No. 7,481,642 issued to Niewels on Jan. 27, 2009.

In additional non-limiting embodiments of the present invention, thefirst passage control member 912 and/or second passage control member914 and/or the third passage control member 916 can be defined as partof the molding stack and as such can be “actuated” by the motion of themold halves, without the need for separate actuator per se.

With reference to FIGS. 11 and 12, there is depicted anothernon-limiting embodiments of the present invention. FIG. 11 depicts asection view of a mold 1000. The mold 1000 includes a mold component1002, which in this case is implemented as a first mold half 1004 and asecond mold half 1006. The first mold half 1004 and the second mold half1006 define therebetween a molding cavity 1008 (defined by respectivefemale and male members of the first mold half 1004 and the second moldhalf 1006). The mold 1000 further includes a passage 1010 that, in use(i.e. during standard molding operation) allows for the evacuation offluid out of the molding cavity 1008 and prevents passage of melt. Thepassage 1010 can be implemented as a vent area.

In the standard molding configuration depicted in FIG. 11, the mold 1000is operated in a standard manner, with the molding cavity 1008 beingfilled with the molding material and the passage 1010 being used forallowing fluid (such as air) to be evacuated from the molding cavity1008 as it is being filled with the molding material.

With reference FIG. 12, a passage cleaning configuration is shown. Inthis configuration the passage 1010, effectively, becomes the extensionof the molding cavity 1008, which can assist in removing residue (notshown) potentially accumulated therein. There are also provided a firstmelt stop 1014 and a second melt stop 1016. The first melt stop 1014 andthe second melt stop 1016 are points for stopping the melt front, in thepassage cleaning configuration. As is best seen when comparing FIG. 11and FIG. 12 illustrations, the first melt stop 1014 and the second meltstop 1016 are in a “closed configuration” in both the standard moldingconfiguration and the passage cleaning configuration. While they are notused in the standard molding configuration per se, they are used as meltfront stops in the passage cleaning configuration.

Needless to say and as is depicted with reference to FIG. 13, the mold1000 can be optionally provided with a passage control member 1200,which can be used to control a secondary vent area, much akin to thedescription of FIG. 9 and FIG. 10 above. The main difference being,however, that the passage control member 1200 is defined as part of themold stack and not as a separate member, as is depicted with referenceto FIG. 9 and FIG. 10.

Accordingly, it can be said that within the architecture of FIGS. 11 and12, there is provided a method of operating a mold, the mold comprisinga first mold half and a second mold half, the first mold half and thesecond mold half defining a passage configured, in use, to allow passageof fluid and to prevent passage of melt, the method comprising:maintaining the mold in a standard molding configuration and executingat least one molding cycle; actuating the first mold half and the secondmold half into a cleaning configuration and executing at least onemolding cycle in the cleaning configuration to remove residue from atleast a portion of the passage.

Accordingly, it can be said that embodiments of the present inventionprovide for a mold component configured to be actuated between: (i) afirst configuration in which the mold component comprises a passage thatallows passage of fluid and prevents passage of the melt; and (ii) asecond configuration in which the passage is actuated such as to becomepart of a molding surface.

With reference now to FIGS. 14 and 14A, another embodiment isillustrated which includes alternate distance augmenting structures,similar to the distance augmenting structure illustrated in FIGS. 8A to8C. FIG. 14 is a cross-sectional view through an injection mold 1100forming part of an injection mold machine (not shown). FIG. 14A is anenlarged view of the portion marked 14A in FIG. 14. As will be explainedhereinafter, the configuration of mold 1100 can be adjusted such that itis configured in a first normal operating mode or in a second alternateoperational mode. In the second operational mode, mold 1100 may beconfigured for vent cleaning in a manner like that described above.Alternatively, the second mode may enable the injection mold 1100 tooperate in another operational mode other than the normal operating modeor a vent cleaning mode.

Generally, mold 1100 may be part of an injection mold machine (notshown) and mold 1110 may include a first mold half generally designated1222 and a second mold half generally designated 1223. First mold half1222 may include a core plate 1103 and a stripper plate 1117, and secondmold half 1223 may comprise a cavity plate 1110. The core plate 1103,stripper plate 1117, and cavity plate 1110 may all be appropriatelysupported on and movable relative to each other on a support frame (notshown) for normal operation of such a mold 1100, in any suitable manneras is well known in the art. A plurality of mold stacks 1111 may also beprovided. The mold stacks 1111 may have components arranged in a stackconfiguration, including components installed in cavities 1191 whichextend through the core plate 1103, stripper plate 1117 and wear plate1119, and cavities 1193, which extend through the cavity plate 1110. Allmold stacks 1111 in mold 1100 may be formed in an identical manner or ina substantially identical manner. Alternatively, in other embodimentsmore than one configuration of mold stack may be provided in the samemold.

It should be noted that while in many, if not most, operational moldslike mold 1100 the orientation would be such that axis X would beoriented generally horizontally and longitudinally in space, axis Yhorizontally and transversely in space, and axis Z vertically in space,these orientations are not necessary. Mutually orthogonal axes X, Y andZ may in other embodiments be arranged in other spatial orientations.

FIG. 14 shows the mold 1100 in a standard operating configuration withthe mold in a closed position ready for injection of molding materialsuch as a plastic into the mold and thus into the plurality of moldstacks 1111 to make production preforms. In FIG. 14, there isillustrated the distance (or height) H in a direction parallel to the Xaxis between the outward facing surface 1143 of core plate 1103 and theinward facing surface 2143 of the cavity plate 1110. In the injectionmolding industry, the distance S in a direction parallel to the X axis,as illustrated in FIG. 14, between the rear surface 1145 of core plate1103 and the forward facing front surface 2145 of cavity plate 1110 istypically referred to as the mold shut height. It will be appreciatedthat as the height H changes, there is a corresponding change in themold shut height S. In the first standard operating mode the height Hwill have a value H1 whereas in a second operating mode the height Hwill have a value H2 that will be different, and typically greater, thanvalue H1. Thus, when the mold 1100 alternates between configurationscorresponding to the first operating mode and the second operating mode,the height H will vary between H1 and H2 and their will be acorresponding change in the shut height S from S1 to S2.

Continuing with reference to FIGS. 14 and 14A, each mold stack 1111 mayinclude a mold core 1102 fitted into the core plate 1103 and retainedtherein by a lock ring 1104. Bolts 1105 may fixedly secure the lock ring1104 to core plate 1103. The position of lock ring 1104 relative to coreplate 1103 remains fixed in the configurations corresponding to thefirst and second operating modes. The mold core 1102 may contain acooling tube 1106 for the transmission of cooling fluid from a sourcewithin the core plate 1103 to remove heat from the injected material inthe mold cavity 1107 and solidify the molded part in the mold cavity1107.

Each mold stack 1111 may also include a cavity insert 1120 and anadjacent gate insert 1129 that are retained in the cavity plate 1110 bya cavity flange 1131. Bolts (not shown) may secure the cavity flange1131 to the cavity plate 1110. Thus, cavity flange 1131 can be fixedrelative to cavity plate 1100 and so there will be no relative movementof the cavity plate 1110 and the cavity flange 1131 as the mold 1100 isalternated between configurations for the first and second operationalmodes referenced above. Cooling channels 1112 may circulate coolingfluid from a source through the cavity insert 1120 and gate insert 1129to remove heat from the injected material.

The mold 1100 may also include one or more pairs of slide bars 1115 aand 1115 b that may be slidably supported on a wear plate 1119. Wearplate 1119 of mold 1100 may comprise a single integrally formed piece ofmaterial with apertures formed therein, or separate sections orsegments, and provide support material for slide bars 1115 a, 1115 bbetween the slide bars and the stripper plate 1117. The wear plate 1119may thus be mounted on the stripper plate 1117. The apertures in thewear plate 1119 may be configured to at receive at least part of regulartonnage blocks 1118 and adaptive tonnage blocks 1113 extending fromcavity place 1110 so that they are able to bear directly against theoutward facing surface of stripper plate 1117, rather than bear againstthe wear plate 1119.

The slide bars 1115 a, 1115 b can be configured for carrying a pair ofneck ring halves 1114 a and 1114 b forming a neck ring associated witheach mold stack 1111. The multiple neck ring halves 1114 a, 1114 b maycommonly be fixedly attached such as with bolts (not shown) torespective slide bars 1115 a, 1115 b. The neck ring halves 1114 a, 1114b, may be formed and configured like neck ring halves of neck ring 300described above and illustrated in FIGS. 3A-3F. The neck ring halves1114 a, 1114 b can slide with slide bars 1115 a, 1115 b respectivelybetween an in-mold first position which corresponds to the “standardmolding configuration” described above in relation to FIG. 3A and anout-mold second position where the neck ring halves are withdrawnsufficiently to allow the ejection process to take place so that aninjected preform can be removed from the mold cavity 1107. Neck ringhalves 1114 a, 1114 b, can be assembled onto and connected to respectiveslide bars 1115 a, 1115 b and this assembly can be moved by connectingbars (such as connecting bars 4030 a, 4030 b as shown in FIG. 18).Connecting bars can include a cam follower (such as rollers 4033 asshown in FIG. 18). These cam followers can be inserted into a cam trackdefined in a cam (not shown). Any forward (ejection) movement ofstripper plate assembly activates a connecting bar movement. Furtherdetails of an example of such an arrangement can be found in Applicant'sUS published patent application, publication no. US-2008/0241309-A1 fora Cam System For A Mold published October 2008, the entire subjectmatter of which is hereby incorporated herein by reference. However,also as known in the art, movement of slide bars 1115 a, 1115 b andtheir respective neck ring halves 1114 a, 1114 b can be effected bymechanisms other than a cam track and roller. By way of example only, inother embodiments, an assembly incorporating a linear actuator might beemployed. In this regard, Applicant's patent published US publishedpatent application no. US2007/0059395 published Mar. 15, 2007, theentire contents of which is hereby incorporated herein by reference,discloses an example of such an alternative mechanism.

The neck ring halves 1114 a, 1114 b, like neck ring 300, also have atleast one additional position and possibly more than one other positionthat may correspond with one or more other additional operational modes.For example, as illustrated, neck ring halves 1114 a, 1114 b may have athird position which corresponds to another operational mode such as a“vent cleaning mode” configuration as discussed above in relation toFIG. 3D in which the neck ring halves may have moved outwardly arelatively small distance. As will be explained hereinafter, in mold1100, the height H between the cavity plate 1100 and the core plate 1103(and thus the corresponding mold shut height S) can be adjusted toincrease and decrease the height H and corresponding mold shut heightand thereby enable the ring halves 1114 a, 1114 b to move between thestandard mold operational configuration and a second operationalconfiguration such as the vent cleaning mode configuration.

The wear plate 1119 is sacrificial material and reduces the wear on thestripper plate 1117 due to movement of the neck ring halves 1114 a, 1114b by the slide bars 1115 a, 1115 b each time a molded part is releasedfrom the mold cavity 1107 and each time the slide bars and neck ringhalves move between the first and second operational modeconfigurations. Cooling channels 1018 may be provided to circulatecooling fluid from a source through the neck ring halves 1114 a and 1114b to remove heat from the injected material. Molten mold material may beconveyed to the mold cavity via a hot runner nozzle, hot runner manifoldand hot runner stacks in a conventional manner known in the art.

It will be appreciated that when the plastic material is injected underpressure into the mold cavity 1107, outward pressure will be exertedupon the neck ring halves 1114 a, 1114 b. To resist this forceassociated with the injected plastic, a clamping (compressive) force Amay be applied to the mold stack 1111 to retain the mold stack 1111 inan appropriate operational configuration, either during standard moldingoperation or during an alternate operation such as vent cleaning. Itwill be appreciated that applying a compressive load A causes reactionforces throughout the mold stack 1111. Thus, due to the inclined matingsurfaces between cavity flange 1131 and neck ring halves 1114 a, 1114 b,a compressive force will act on neck ring halves 1114 a, 1114 b alongthe longitudinal (X) and transverse (Y) axes, urging the neck ringhalves 1114 a, 1114 b, transversely inwards. In this way, by applicationof a suitable compression force, the relative positions of the neck ringhalves 1114 a, 1114 b can be held at either the desired standard moldingconfiguration or the vent cleaning configuration, which can bedetermined by the selection of the appropriate mold shut height S.

With the application of clamping force A to the mold stack 1111, littleif any of this load will typically be carried through the slide bars1115 a, 1115 b or wear plate 1119 or stripper plate 1117. In the normaloperating configuration, additional load may be provided to compress thecore plate 1103 and the cavity plate 1110 together and load may betransmitted also from the cavity plate 1110, through regular tonnageblocks 1118 (FIGS. 14 and 14A) into the stripper plate 1117 and to thecore plate 1103. In a second operational configuration, such as a ventcleaning mode, the stack 1111 may be in an “open” configuration withsubstantially no compressive load being transmitted through the stack1111. A compressive load may however still be provided to compress thecore plate and the cavity plate together and may be transmitted alsofrom the cavity plate 1110, through adaptive tonnage blocks 1113 (FIGS.14 and 14A) into the stripper plate 1117 and to the core plate 1103 aswill be described further below.

When the mold 1100 is in the standard operating configuration, theclamping force A being applied to the stack may be greater than theminimum load which would be required to resist injection pressure andhold the mold stack components in position. Additional compressiveloading provides safety in case of processing or melt qualityfluctuations which would result in preform flash during normaloperation. Thus, the conventional or regular tonnage blocks 1118 maybear additional load in co-operation with cavity plate 1110, stripperplate 1117 and core plate 1103. The height of the regular tonnage blockscan be selected to provide an appropriate/desired distance between thecavity plate 1110 and the stripper plate 1117. Thus, in most normaloperating configurations, the tonnage blocks 1118 are positioned betweenand space the cavity plate 1110 and stripper plate 1117, and thusprovide a height H and shut height S of distances required for thestandard operational configuration for producing performs. As notedabove, regular tonnage blocks 1118 are received in apertures in the wearplate 1119, so that load borne by the regular tonnage blocks 1118 istransferred to the stripper plate 1117. It would only be in anexceptional situation where a wear plate 1119 would be used to transmitcompressive loads between the cavity plate and the core plate with thetonnage blocks engaging the wear plate.

As will be described further below, adaptive tonnage blocks 1113 mayalso be provided and the position of the engaging surface of theadaptive tonnage blocks can be selected to provide an increased distancebetween the cavity plate 1110 and the stripper plate 1117 providing aheight H (and corresponding shut height S) of a distance required forthe alternate operational configuration.

Mold 1100 may be provided with a mold shut height adjustment apparatusthat may comprise one or more distance augmenting structures. Inparticular, the mold shut height adjustment apparatus may comprise oneor more of three separate mechanisms to cause an adjustment of theheight H (and thus also an adjustment of the mold shut height S) and/oran adjustment of the configuration of the neck ring halves between thestandard molding configuration and a second operational modeconfiguration such as the vent cleaning configuration. The mold shutheight adjustment mechanisms may be integrated and at least partiallyembedded within one or both of the mold halves 1222, 1223. Three suchmechanisms can be characterized as: (1) a cavity plate adjustmentmechanism 2000; (2) a neck ring adjustment mechanism 4000; and (3) acore plate adjustment mechanism 3000. Of these, the cavity plateadjustment mechanism 2000 and core plate adjustment mechanism 3000 maycause an adjustment of mold shut height, and this may indirectly duringoperation result in an adjustment of the configuration of the neck ringhalves 1114 a, 1114 b.

With respect to core plate adjustment mechanism 3000, its function is toadjust the distance between core plate 1103 and stripper plate 1117. Byincreasing the space between the core plate 1103 and stripper plate1117, the position of lock ring 1104 relative to neck ring halves 1114a, 1114 b can be adjusted. Specifically, the neck ring halves 1114 a,1114 b can move longitudinally away from lock ring 1104. As will bedescribed later, a corresponding adjustment of a distance between cavityplate 1110 relative to stripper plate 1117 can allow cavity flange 1131to move (longitudinally) relative to the inclined surface of the neckring halves 1114 a, 1114 b. This movement can be facilitated by cavityplate adjustment mechanism 2000, to allow neck ring halves 1114 a, 1114b to move outwardly from the standard molding configuration to a ventcleaning configuration as described above.

With particular reference to FIGS. 15, 16 and 16A to 161, core plateadjustment mechanism 3000 comprises a plurality of core plate adjustmentdevices 3001 that may be referred to herein as back up pads. The back uppads 3001 may be received in recesses or apertures 3016 defined in thecore plate 1103. As is best shown in FIG. 28, and as will be more fullydescribed hereinafter, in an alternate operational configuration, theback up pads 3001 may be extended to space stripper plate 1117 apartfrom core plate 1103. Accordingly, the plurality of back up pads 3001may be spaced in appropriate locations about core plate 1103 to providefor a proper or appropriate loading distribution between the core plateand stripper plate 1117 when the back up pads 3001 are engaged toprovide a separation of the core plate 1103 from the stripper plate 1117(the stripper plate not being shown in FIG. 15 and FIGS. 16A-16G).

As is best shown in FIGS. 15 and 16F, each back up pad 3001 mayintegrated within and be partially embedded in core plate 1103. Eachback up pad 3001 may include an engagement portion 3008 having anengagement surface 3023. Engagement portion 3008 is moveable in adirection parallel to axis X from a first, retracted position where theengagement surface 3023 is generally flush with, or reset behind, thesurface 1143 of the core plate 1103 to a second, extended position wherethe engagement surface 3023 extends past surface 1143 of core plate1103. When the engagement surface 3023 is at the first (retracted)position generally flush with, or reset behind, surface 1143 of the coreplate 1103, the mold 1100 may be in its standard mold operatingconfiguration. When the engagement surface is in its second (extended)position, the injection mold 1100 may be in an alternate operationalconfiguration such as a vent cleaning configuration.

With particular reference to FIGS. 16E and 16F, in addition toengagement portions 3008, each back up pad 3001 may have a drivingportion 3006 which is moveable with a sliding motion between first andsecond positions. Driving portion 3006 may have a flat surface 3033which rests against an adjacent surface of the core plate 1103 in theaperture 3016 in the core plate. Thus, a load on the driving portion3006 acting in the direction parallel to axis X towards the core plate1103 can be transmitted to the core plate 1103. In a first position(shown in FIGS. 16F and 16H) the driving portion 3006 is in a firstposition where protrusions 3007 on its surface are received incorresponding recesses 3005 on the surface of the engagement portion3008.

Similarly, in such a first position, protrusions 3004 on the engagementportion may be received by corresponding recesses 3002 on drivingportion 3006. Driving portion 3006 may be moved from the position (shownin FIGS. 16F and 16H) in a direction parallel to axis Z to a secondposition (as shown in FIG. 16I) where protrusions 3007 on the surface ofdriving portion 3006 push and cam against the protrusions 3004 on thesurface of the engagement portion 3008 and move to a position where theprotrusions 3007 are generally aligned with protrusions 3004 in the Zdirection. This has the effect of causing the engagement portions 3008of back up pads 3001 to move away from core plate 1103 in a directionparallel to the X axis. In this position a space can be created betweenthe adjacent surface 1143 of core plate 1103 and the adjacent surface1147 of stripper plate 1117. The engagement portion 3008 and the drivingportion 3006 of each back up pad device 3001 may be made from anysuitable material such as by way of example stainless steel.

The movement of engagement portion 3008 is limited to the aforementionedsliding movement parallel to the X axis. This limited movement may beaccomplished in many ways. For example, as is best shown in FIG. 16F, apair of spaced bolts 3011 may be provided proximate opposed ends of thedriving portion 3006, the bolts having shafts that are generally axiallyaligned with axis X. The shafts of bolts 3011 may have bottom threadedend portions 3014 that are received in corresponding threaded apertures3013 in the core plate 1103. Shafts of bolts 3011 may also have upperportions that at their upper end are integrally connected with boltheads 3009. Each bolt 3011 may be received in a generally cylindricalpad aperture 3017 that passes entirely through engagement portion 3008.The movement within the pad apertures 3017 will be guided by the contactwith the outer side surfaces of the bolt heads. Each pad aperture 3017may have a shoulder portion 3017 a. Between the bottom surface of bolt3011 and the upper surface of shoulder portion 3017 a is a gap 3015. Itwill be appreciated that the engagement portion 3008 of back up pad 3003may move in a direction parallel to axis X as the bolt heads 3009 movewithin their respective apertures 3017 between an extended outwardposition where the shoulders 3017 a abuts the lower surfaces of the boltheads 3009, and an inward retracted position where the protrusions 3004of the engagement portion 3008 are transversely aligned and in abutmentwith the recesses 3002 of the driving portion 3006 (i.e. the engagementportion 3008 is fully retracted).

Optionally, the engagement portion 3008 may be force biased to theretracted position by a biasing mechanism. For example, the drivingportion 3008 may biased to the retracted position by a spring mechanism.The spring mechanism may include a coil spring 3018 retained undercompression between each one of bolt heads 3009 and the upper surface ofthe corresponding shoulder portion 3017 a as shown in FIG. 16F.

With particular reference now to FIGS. 16A, 16E and 16G, it can beobserved that to cause driving portion 3006 to be driven inreciprocating movement in a direction parallel to axis Z, drivingportion 3006 may be secured to a connecting rod 3030 that generally runsin a direction parallel to axis Z. Connecting rod 3030 may be attachedto driving portion 3006 by, for example, a series of interlocking teeth3090 (FIG. 16E) on both the driving portion and connecting rod. However,other suitable attachment modes will be apparent to skilled persons,such as by way of example only welding or bolts. Connecting rods 3030may be made from any suitable material, such as by way of example onlyheat-treated steel. A single rod 3030 may be attached to drivingportions 3006 of one or more back up pad devices 3001. For example, therod 3030 depicted in the cross sectional view of FIGS. 16B and 16E isattached to two driving portions 3006 of separate and aligned back uppad devices 3001.

With particular reference again to FIG. 16A, a plurality of connectingrods 3030 may be provided so that the driving portion 3006 of each backup pad device 3001 in the core plate 1103 may be connected to at leastone connecting rod 3030. The plurality of connecting rods 3030, whichall may extend and be aligned in a direction parallel to axis Z, may bethemselves be all interconnected by any known and suitable attachmentmechanism such as for example bolting, welding etc. to a common actuatorcross bar 3035 that may be made from any suitable material such as byway of example only stainless steel. Actuator cross bar 3035 may beoriented in a direction generally orthogonal to the connecting rods andextend generally in a direction parallel to axis Y. Connecting rods 3030may in some embodiments such as is illustrated in FIGS. 15-16G, behoused and moveable within enclosed channels that extend within the bodyof the core plate 1103, and thus will be generally not be visible whenlooking at the core plate such as in the view shown in FIG. 15. Thusconnecting rods 3030 and actuating bar 3035 may together constitute aconnection mechanism to connect the driving portion 3006 with anactuator. In other embodiments, the connecting rods 3030 may be housedand moveable within open channels where the channels are formed aslongitudinally extending grooves defined in the core plate 1103 at theoutward facing surface 1143 of core plate 1103

Actuator cross bar 3035 may in turn be secured in a suitable manner toan actuating device 3045 (FIG. 16A) such as a drive shaft of a servomotor or a pneumatic piston. The actuating device 3045 may be operatedunder the control of a controller 3050, such as, for example, aprogrammable logic controller (PLC) or industrial computer. Actuatingdevice 3045 may thus have a communication link to the controller 3050which may be wired or wireless. Actuating device 3045 may be mountedwithin the core plate with screws connecting it to the core plate.Actuating device 3045 may have an actuating shaft (not shown) operablefor intermittent, controlled, reciprocating movement back and forth indirections that are generally parallel to axis Z. Thus actuating device3045 and its reciprocating shaft is interconnected to actuator cross bar3035, which in turn is connected to each of the connecting rods 3030.The connecting rods 3030 are in turn are interconnected to drivingportions 3006 of back up pad devices 3001. Thus, cyclical, intermittentbackward and forward movement of the actuating shaft of the actuatingdevice 3045 can result in synchronized movement of each driving portions3006 of all back up pad devices in a direction parallel to axis Z, andthus the synchronized extension of all engagement portions 3008 in thedirection parallel to axis X. By way of example only, actuator shaft ofactuating device 3045 may be moved about 10 mm in a direction parallelto axis Z, resulting in a corresponding movement parallel to the Z axisof the connecting rods 3030 and the driving portions 3006 of the back uppad devices 3001. The engagement of driving portions 3006 withengagement portions 3008 may translate into 0.5 mm movement of theengagement portions 3008 in a direction parallel to axis X to result ina 0.5 mm separation between the adjacent surfaces of the core plate 1103and the stripper plate 1117.

It will be appreciated that this movement of the engagement portions3008 of back up pad devices 3001 will typically be carried out when themold stack 1111 is not under a clamping force A and when most if not allcompressive forces acting on the core plate 1103 and stripper plate 1117have been removed, allowing the stripper plate 1117 to be displaced in adirection parallel to the X-axis. For example, movement of engagementportions 3008 may typically be effected with the mold 1100 fully openfor ejection of performs or other parts. Once the extended position ofthe engagement portions 3008 has been reached, however, the engagementportions 3008 will be able to maintain their extended position once thecompressive loads are re-applied, during operation in the second modesuch as vent cleaning, and load will be transmitted through the drivingportions 3006 to the core plate 1103.

It will be appreciated that other alternate mechanisms may be providedto effect movement of the engagement portion 3008 of each back up paddevice 3001 between the retracted and extended positions.

In the embodiment of FIGS. 15 and 16A-16G, some parts of neck ringadjustment mechanism 4000 are also shown. In particular, a pair ofspaced, generally L-shaped, actuating blocks 4010 are integrated withand at least partially embedded and received within apertures 4013 inthe outer surface 1143 of core plate 1103 (see also FIGS. 20A-G). Eachactuating block 4010 has opposed engagement faces 4014 a, 4014 b. Eachengagement face 4014 a, 4014 b, may contain a spring-loaded thrust paddevice 4012 a, 4012 b that may be in the form of a thrust pad have agenerally semi-spherical surface for engaging one of a dowel or othermember 4032 a, 4032 b (FIGS. 20B-20C; the position of thrust pads 4012a, 4012 b is also shown in broken line in FIG. 20D), on a slide barconnecting bar 4030 a, 4030 b as will be explained further hereafter.Thrust pad portions 4012 a, 4012 b may be resiliently displaceable indirections parallel to axis Y relative to the remaining parts of block4013. For example the thrust pad portions 4012 a, 4012 b, may bereceived in opposed channels in block 4013 and be spring loadedproviding a spring force created by a spring (not shown) that on eachthrust pad portion, tends to exert an outwardly directed force. Thethrust pad portions 4012A, 4012B may be held in the channel by aretaining ring (not shown)

Each actuating block 4010 is adapted to be able to slide in back andforth in directions parallel to axis Z within the core plate aperture4013. Each actuating block 4010 may be supported for such slidingmovement within the aperture 4013 by having a base leg 4019 of theactuating block supported upon a base 4015 surface within the aperture4013. The aperture 4013 may also be provided with a cover 4017 (FIGS.20B-20C) which can be releasably attached to the core plate 1103 withbolts 4035 (FIG. 20E) that may be received in threaded apertures 4037 incore plate 1103. The base leg 4019 of the actuating block 4010 may thusmove in sliding movement in the channel provided by aperture 4013 andtop cover 4017

Each actuating block 4010 may be also secured to one of the connectingrods 3030. Actuating blocks 4010 may be attached to the same connectingrods that are also connected to driving portions 3006 of back up paddevices 3001. The connection of the actuating blocks 4010 to theconnecting rods can be effected in the same way as driving portions 3006of back up pads 3001, for example, using interlocking teeth, or in anyother suitable manner such as for example welding or bolting.Alternatively, a separate driving mechanism, such as for exampleincluding separate connecting rods, may be provided for actuating blocks4010. Thus, actuating blocks 4010 may also be moved in reciprocating,intermittent movement in directions parallel to axis Z. This movementcan cause the thrust pad devices 4012 a, 4012 b to engage withrespective dowels 4032 a, 4032 b depending from slide bar connectingbars 4030 a, 4030 b respectively, causing a cam effect that translatesinto driving the slide bar connecting bars 4030 a, 4030 b respectivelyto move in opposite outward directions parallel to axis Y Similarly, amovement in an opposite direction can cause thrust pad devices 4012 a,4012 b, to disengage from respective dowels 4032 a, 4032 b allowing theslide bars to move in opposite inward directions parallel to axis Y.When the thrust pad devices 4012 a, 4012 b disengage, the slide barconnecting bars 4030 a, 4030 b move in the opposite direction and canreturn to their standard operational configuration. Because in suchconfiguration, the stack will be closed, the tapered surface on the neckring halves 1114 a, 1114 b, engaged with the opposed tapered surface onlock ring or cavity flange can create a force to drive the slide barconnecting bars 4030 a, 4030 b in the opposite direction. The restoringforce results from the clamping force applied to the stack and onto theneck ring halves 1114 a, 1114 b and thus the slide bars 1115 a, 1115 b.

Turning now to FIGS. 17, 18, 19, and 20A, various perspective views areshown of different sub-assemblies comprising components of mold 1100,with each of these views showing a different number of components thanthe other views. In FIG. 17, core plate 1103 is shown with stripperplate 1117 mounted above it, and wear plate 1119 mounted above thestripper plate. The sliding bar connecting bars 4030 a, 4030 b arereceived in channels formed through stripper plate 1117 and wear plate1119 (see in particular FIGS. 15 and 16). These channels are oriented ina direction generally parallel to axis Y. The slide bar connecting bars4030 a, 4030 b can each be joined to one of slide bars 1115 a, 1115 bsuch as with bolts (not shown). Each of the plurality of neck ringhalves 1114 a, 1114 b is mounted to one of slide bars 1115 a, 1115 b. Itwill be appreciated that the plurality of neck ring halves 1114 a, willmove with slide bar 1115 a in reciprocating movements in a directionparallel with axis Y. Similarly, the plurality of neck ring halves 1114b, will move with slide bar 1115 b in opposite reciprocating movementsbut still in directions parallel with axis Y. Thus the neck ring halves1114 a, 1114 b may be moved towards each other or away from each other,as required by the particular mode in which the injection mold 1100 isoperating.

With particular reference now to FIGS. 20A, 20B and 20C, neck ringadjustment mechanism 4000 may be operated as follows. Each actuatingblock 4010 being secured to one of the connecting rods 3030 may be movedby the actuator bar 3035 connected to actuating device 3045 (see FIG.16A), in reciprocating, intermittent movement in directions parallel toaxis Z. This movement (which will move in synchronized operation withcore plate adjustment mechanism 3000) can cause the thrust pad devices4012 a, 4012 b to engage with the respective dowels 4032 a, 4032 b onslide bar connecting bars 4030 a, 4030 b respectively, causing a cameffect that translates into driving the slide bar connecting bars 4030a, 4030 b respectively to move in opposite outward directions, but indirections parallel to axis Y. With particular reference now to FIGS. 17and 18, when connecting bars 4030 a are moved in an outward directionparallel to axis Y, this will move slide bars 1115 a, and the neck ringhalves 1114 a attached thereto, in the same direction. Similarly whenconnecting bars 4030 b are moved in an outward direction parallel toaxis Y, but opposite to connecting bars 4030 a, this will move slidebars 1115 b, and the neck ring halves 1114 b attached thereto, in theopposite direction to neck ring halves 1114 a, and slide bars 1115 b.Thus, neck ring halves 1114 a, 1114 b can be moved outwards away fromeach other to a position where they are configured for operation of theinjection mold 1100 in the alterative operational mode such as the ventcleaning mode configuration. This movement will occur in synchronizationwith the separation of stripper plate 1117 from core plate 1103 by coreplate adjustment mechanism 3000 as described above and as particularlyillustrated in FIGS. 16H and 16I. Thus, actuating device 3045 undercontrol of CONTROLLER 3050 can serve as the actuating driver for bothcore plate adjustment mechanism 3000 and neck ring adjustment mechanism4000. Neck ring adjustment mechanism 4000 can be suitably configured towork co-operatively with the core plate adjustment mechanism 3000 asdescribed above.

Turning now to cavity plate adjustment mechanism 2000 (FIG. 23A), itspurpose is to adjust the spacing between the cavity plate 1110 and thestripper plate 1117 and thus can also modify the height H andcorresponding mold shut height S. This will allow for adjustment in thedistance in the X direction between the cavity flange 1131 relative tothe neck ring halves 1114 a, 1114 b.

With particular reference to FIGS. 22, 23A-C, 24 and 25 cavity plateadjustment mechanism 2000 may comprise a plurality of cavity plateadjustment devices 2001 that may be referred to herein as adaptivetonnage blocks 1113. The adaptive tonnage blocks 1113 may be integratedwith and at least partially embedded within cavity plate 1110. In thisembodiment adaptive tonnage blocks 1113 are arranged in two rows, eachrow having four aligned adaptive tonnage blocks 1113. The plurality ofadaptive tonnage blocks 1113 may be spaced in any appropriate locationsabout cavity plate 1110 to provide for a proper loading distribution onthe cavity plate 1110 and stripper plate 1117 when the adaptive tonnageblocks 1113 are engaged to provide an additional distance separation ofthe cavity plate 1110 from the wear plate 1119.

In addition to the adaptive tonnage blocks 1113, regular tonnage blocks1118 as referenced above, may also be provided as shown in FIGS. 22 and23A. Additionally, four reflex tonnage blocks 1188 (also referred to asa regulating tonnage structures) may optionally be provided, with onereflex tonnage block being positioned at each one of the four corners ofthe cavity plate 1110. Applicant's own U.S. Pat. No. 8,348,657 issuedJan. 8, 2013 discloses examples of such structures that may be employed.

Each of the adaptive tonnage blocks 1113 extends in the X and Zdirections and may be received in a respective recess or aperture 2016in the inward surface 2143 of cavity plate 1110. Each adaptive tonnageblock 1113 may include an engagement portion 2008 having an engagementsurface 2023 (FIG. 24). Engagement portion 2008 may have a separationblock 2018 fixedly secured thereto with bolts 2079 (FIG. 25) passingthorough apertures in separation block 2018 and received into threadedapertures in the bottom surface of each engagement portion 2008. Thus,separation block 2018 can be configured for movement with engagementportion 2008. In some embodiments engagement portion 2008 and separationblock 2018 may be integrally formed as a combined unitary portion of atonnage block 1113.

With particular reference to FIGS. 26A and 26B, each engagement portion2008 and separation block 2018 are moveable together in a directionparallel to axis X: between (a) a first (retracted) position (FIG. 26A)where the engagement surface 2023 is a first distance D1 from thesurface 2143 of the cavity plate 1110 and (b) a second (extended)position (FIG. 26B) where the engagement surface 2023 is positioned asecond distance D2 spaced away from the front of surface 2143 of cavityplate 1110. In the retracted position, tonnage block 1113 may be atleast partially received in an aperture in wear plate 1119 and a gap maybe left between engagement surface 2023 and stripper plate 1117. Withtonnage block 1113 in this position, the distance between the opposingsurfaces of the stripper plate 1117 and cavity plate 1110 is defined bythe mold stack 1111 and the regular tonnage blocks 1118, and D1 (i.e.the distance between the engagement surface 2023 of the tonnage block1118 and the surface 2143 of the cavity plate 1110 in the retractedposition) is no more, and possibly is less, than the height of theregular tonnage blocks 1118. In the extended position, tonnage block1113 is fully received in an aperture in wear plate 1119 and theengagement surface 2023 of engagement portion 2008 is in abutment withthe surface 2119 of the stripper plate 1117. But distance D2 (i.e. thedistance between the engagement surface 2023 of the tonnage block 1118and the surface 2143 of the cavity plate 1110 in the extended position)is greater than D1 and the height of regular tonnage blocks 1118 andthus the distance between the opposing surfaces of the cavity plate 1110and the stripper plate 1117 is increased by extension of the adaptivetonnage blocks 1113. Thus the height H and corresponding mold shutheight S can be increased.

When the engagement surface 2023 is at the first (retracted) position(FIG. 26A) the injection mold 1100 may be in its standard mold operatingconfiguration. When the engagement surface 2023 of the adaptive tonnageblock 1113 is in its second (extended) position (FIG. 26B), theinjection mold 1100 may be in an alternate operational configurationsuch as for example the vent cleaning operational configuration. Themovement of the adaptive tonnage blocks 1113 may be coordinated with themovement of core plate adjustment mechanism 3000 and neck ringadjustment mechanism 4000 as described above.

With particular reference to FIGS. 24, 25, 26A and 26B, in addition toengagement portions 2008 and separation blocks 2118, each adaptivetonnage block 1113 may have a driving portion 2006 which is moveablewith sliding motion in a direction parallel to the Z axis between firstand second positions. The driving portion 2006 may be received withapertures 2016 in the cavity plate 1110 and driving portion 2006 has asurface 2033 which rests against an adjacent surface of the cavity plate1110 in the apertures 2016 in the cavity plate. Thus, a load on thedriving portion 2006 acting in the direction parallel to axis X towardsthe cavity plate 1110 can be transmitted to the cavity plate 1110. Inthe first position (shown in FIGS. 24 and 26A), upper protrusions 2007on the surface of driving portion 2006 are received in recesses 2005 onthe rear surface of the separation block 2018.

Similarly, in such a position, the recesses 2002 on driving portion 2006may receive protrusions 2004 on the separation block 2018. In such aposition, all the protrusions may not engage or at least are in such aposition that the engagement portion 2008 is in its first positionreferenced above. Driving portion 2006 may be moved from the positionshown in FIGS. 24 and 26A in a direction parallel to axis Z to aposition shown in FIG. 26B where upper protrusions 2007 on its surfacecam against the protrusions 2004 on the adjacent surface of theseparation block 2018 and move the separation block 2018 along withengagement portion 2008 to a position where the protrusions 2007 aregenerally aligned with protrusions 2004 in the Z direction. This has theeffect of causing the engagement portions 2008 to move outwardly in adirection parallel to the X axis. In this position an additionalseparation distance will be created between the opposed surface 2143 ofcavity plate 1103 and the surface 2119 of stripper plate 1117.

The movement of engagement portion 2008 and separation block 2018 islimited to the aforementioned back and forward movements parallel to theX axis. This limited movement may be accomplished in many ways. Forexample, a pair of spaced pin members 2011 (FIG. 25) may be providedproximate opposed ends of the engagement portion 2006 having shafts thatare generally axially aligned with axis X. The shafts of pins 2011 mayhave bottom threaded end portions 2014 that pass through the engagementportion 2008, separation block 2018 and driving portion 2006 of adaptivetonnage blocks 1113 and are received in corresponding threaded aperturesin the cavity plate 1110. Thus the pins 2011 secure the adaptive tonnageblocks 1113 to the cavity plate 1110. Shafts of pins 2011 may also haveupper portions that at their upper end are integrally connected withheads 2009. Each pin 3011 may be received through a generallycylindrical sleeve tube 2089 that may be itself be housed in a generallycylindrical pad aperture 2017 that passes entirely through engagementportion 2008. The sleeve 2089 may also be housed within and pass throughan aligned aperture in separation block 2018. Below each pin head 2009of pin 2011 is a shoulder portion 2069 and beneath the shoulder 2069 isa spring 2099 which engages and is retained in compression betweenshoulder 2069 and separation block 2018. Spring 2099 may fit around theouter surface of sleeve 2089. Engagement portion 2008 and separationblock 2018 may slide up and down relative to sleeve 2089. Thus, whenengagement portion 2008 and separation block are moved by drivingportion 2006, there will be a restoring force exerted by the spring 2099as it is held between the shoulder 2069 and separation block 2018. Itwill be appreciated that the engagement portion 2008 may move in adirection parallel to axis X as the apertures slide over pins 2011between an extended position, and a retracted position where theprotrusions 2004 of the separation block 2018 are transversely alignedand in abutment with the recesses 2002 of the driving portion 2006 (i.e.the engagement portion 2008 is fully retracted).

With particular reference now to FIGS. 23A and 24 it can be observedthat to cause driving portion 2006 to be driven in reciprocatingmovement in a direction parallel to axis Z, driving portion 2006 may besecured to a connecting rod 2030 that generally runs in a directionparallel to axis Z. Driving portion 2006 may be secured to connectingrod 2030 by interlocking teeth 2121 (FIG. 23C) or by other suitablemethods such as by way of example welding or bolting. Engagement portion2008, separation block 2018 and driving portion 2006 may be made of anysuitable material such as by way of example stainless steel. Similarly,connecting rods 2030 may be made from any suitable material such as byway of example a heat-treated steel. A single rod 2030 may be attachedto driving portions 2006 of one or more aligned back up pad devices3001. For example, the rod 2030 depicted in the cross sectional view ofFIG. 23B is attached to four driving portions 2006 of separate adaptivetonnage blocks 1113.

A plurality of connecting rods 2030 may be provided so that the drivingportion 2006 of each adaptive tonnage block 1113 in the cavity plate1110 may be connected to at least one connecting rod 2030. The pluralityof connecting rods 2030, which all may be aligned in a directionparallel to axis Z, may be themselves be all interconnected by any knownand suitable attachment mechanism such as bolting, welding etc. to acommon actuator cross bar 2035 that may be made from any suitablematerial such as by way of example only stainless steel.

Actuator cross bar 2035 may be oriented in a direction generallyorthogonal to the connecting rods and generally parallel to axis Y. Thusconnecting rods 2030 and actuating bar 2035 may together constitute aconnection mechanism to connect the driving portion 2006 with anactuator. Connecting rods 2030 may in some embodiments such as isillustrated in FIGS. 22 and 23A be housed and moveable within enclosedchannels that extend within the body of the cavity plate 1110, and thuswill be generally not be visible when looking at the cavity plate suchas in the view shown in FIG. 19. In other embodiments, the connectingrods 2030 may be housed and moveable within open channels where thechannels are formed as longitudinally extending grooves defined in thecavity plate and at the inward facing surface of cavity plate 1110.

Actuator bar 2035 may in turn be secured in a suitable manner to anactuating device 2045 (FIG. 23A) such as a servo motor, pneumaticpiston, under the control of controller 3050. Actuating device 2045 mayhave an actuating shaft (not shown) capable of providing intermittent,controlled, reciprocating movement back and forth in directions that aregenerally parallel to axis Z. Actuating device 2045 may thus havecommunication link to the controller 3050. Actuating device 2045 may bemounted within the cavity plate 1110 with screws connecting it to thecavity plate 1110. By means of the interconnection of actuating device2045 and its reciprocating shaft interconnected to actuating cross bar2035, which in turn is connected to each of the connecting rods 2030,which in turn are interconnected to driving portions 2006 of adaptivetonnage blocks 1113, cyclical, controlled and intermittent movement ofthe actuating shaft of the actuating device 2045, may result insynchronized movement of each driving portions 2006 in a directionparallel to axis Z, and thus the synchronized movement of all engagementportions 2008 in the direction parallel to axis X. By way of exampleonly, actuator shaft of actuating device 2045 may be moved about 10 mmin a direction parallel to axis Z, resulting in a corresponding movementparallel to the Z axis of the connecting rods 2030 and the drivingportions 2006 of the back up pad devices 3001. The engagement of drivingportions 2006 with separation blocks 2018 and thus engagement portions2008 may translate into 0.5 mm movement of the engagement portions 2008in a direction parallel to axis X to result in an increase in separationof 0.5 mm separation between the opposed surfaces of the cavity plate1110 and the stripper plate 1117. Under the control of CONTROLLER 3050,this may occur in a coordinated fashion with the movement of neck ringhalves 1114 a, 1114 b in a direction parallel to the Y-axis and themovement of back up pads 3001 in a direction parallel to the X-axis.

During normal molding use, core plate 1103 and cavity plate 1110 will becycled to a closed position as shown in FIG. 14 with the mold stacktherebetween providing a first operational configuration for the mold1100. While in this position, the mold stack 1111 is subjected tocompressive clamping force A (FIG. 14A) as mold material is injected andthen cooled and hardened. Subsequent to cooling of parts, the stack ismoved from its normal operational configuration and cycled to its openposition (FIG. 27), in which the clamping force is released and the coreand cavity plates are spread longitudinally relatively apart, thustaking on a non-operational configuration (i.e. the mold is not in aconfiguration where it is being operated to inject mold material intothe mold cavities). In the mold open configuration, finished parts areejected in a conventional manner as the stripper plate 1117 slides awayfrom the core plate 1103 and, slide bars 1115 a, 1115 b and neck ringhalves 1114 a, 1114 b are moved laterally outwardly to the positionshown in FIG. 27. During this normal operation, vents in neck ringhalves 1114 a, 1114 b may function substantially as described above withreference to FIGS. 3 a-3 c. That is, vents in neck ring halves 1114 a,1114 b may permit gas to escape, but prevent substantial quantities ofinjected mold material from entering the vents. In such normaloperation, in order for the mold stack to close to the desired moldingconfiguration, each of the cavity plate adjustment mechanism 2000 andcore plate adjustment mechanism 3000 operate in their first (retracted)conditions, and neck ring adjustment mechanism 4000 operates in itsfirst (normal) condition as described above. The positions of the moldstack components in the closed state of this normal molding operationare as depicted in FIG. 14A.

Periodically, it may be desired to place the mold 1100 in an alternateoperational configuration, such as an operational configuration whichcan clean vents as described above. As will be appreciated from theforegoing description, cleaning may entail providing additionalclearance between neck ring halves 1114 a, 1114 b to increase vent size.At the beginning of a cleaning cycle, the mold 1100 may be open as shownin FIG. 27. Actuating device 3045 may then be cycled to cause back uppads 3001 to be extended, which will result in core plate 1103 beingspaced apart from stripper plate 1117 and the neck ring halves 1114 a,1114 b. As noted, cycling of actuating device 3045 also causes movementof actuating blocks 4010 so that thrust pad devices 4012 a, 4012 b pushthe slide bars 1115 a, 1115 b and therefore the neck ring halves 1114 a,1114 b apart. Meanwhile, actuating device 2045 may cause adaptivetonnage blocks 1113 to be extended, which in turn causes cavity plate1110 and stripper plate 1117 to have an increased spacing apart from oneanother. As will now be appreciated, this provides lateral clearancepermitting the neck ring halves 1114 a, 1114 b to be held spaced apart.The mold may then be closed, by appropriate relative movement betweenthe cavity plate 1110 and the wear plate 1119, stripper plate 1117 andcore plate 1103, but without application of any significant clampingforce A.

In this alternate (cleaning) operational configuration, the componentsof the mold stack are positioned as shown in FIG. 28 when the mold stackis closed. In this condition, an enlarged gap exists between the neckring halves as shown in FIG. 3D. Once the mold components are in thisconfiguration, clamping force A may be applied. In some embodiments,clamping force A may be reduced relative to the clamping force that isapplied during normal molding operation. In other embodiments, theclamping force could be the same or even greater than in the normaloperational mode. This might be required because the molding material isacting on a larger surface area of the components. Molding material isthen injected and cooled and molded parts are ejected substantially asdescribed above. Due to the spacing apart of neck ring halves 1114 a,1114 b during molding, molding material occupies the enlarged ventswhich may have the effect of removing residue from the vents asdescribed above. This may also result in excess flash material onfinished parts. Such parts may therefore be discarded.

In other embodiments, cycling of actuating device 3045 and actuatingdevice 2045 may occur with the mold in the position depicted in FIG.28—that is with the mold closed. In such a case, mold components may bepushed to their alternate (cleaning) configurations with cavity plateadjustment mechanism 2000, core plate adjustment mechanism 3000 and neckring adjustment mechanism 4000 being operated so that the componentsadopt their alternate configurations.

In other embodiments, the cavity plate adjustment mechanism, core plateadjustment mechanism and the neck ring adjustment mechanism may be usedalone or in combination to selectively create spacing between mold stackcomponents for reasons other than vent cleaning. In some embodiments,all or some of core plate adjustment devices 3001 and cavity plateadjustment devices 2001 could be provided with individual activationinstead of having connectors like 2030 or 3030. Individual activationcould be done by hydraulic and/or pneumatic device (cylinder) or byservo drives (electrical).

As an alternative, or even in addition, to employing the mold shutheight adjustment apparatus described herein for vent cleaning, theapparatus may also be used to implement the method described in commonlyassigned US patent publication 2012/0219651 to Weber et al., publishedon Aug. 30, 2012. Specifically, the present non-limiting embodiments ofthe mold shut height adjustment apparatus may be useful in implementinga pressure-control system in an injection mold for selectively changinga volume of a mold cavity defined within the mold after isolationthereof from a stream of molding material. A technical effectattributable to the foregoing may include, amongst others, providing apre-eject function while maintaining contact between the molded articleand the molding surfaces of the mold cavity.

It should be understood that for the purposes of the descriptionprovided above and claims presented below, the term “fluid”, “gas” or“air” are meant to denote fluid present in the molding cavity and beingvented from the molding cavity and the molding material fills in themolding cavity. The terms “fluid”, “gas” or “air” can denote ambient airaround the molding system, as well as the ambient air mixed in withother substances potentially present within the molding system.

The description of the embodiments of the present inventions providesexamples of the present invention, and these examples do not limit thescope of the present invention. It is to be expressly understood thatthe scope of the present invention is limited by the claims only. Theconcepts described above may be adapted for specific conditions and/orfunctions, and may be further extended to a variety of otherapplications that are within the scope of the present invention. Havingthus described the embodiments of the present invention, it will beapparent that modifications and enhancements are possible withoutdeparting from the concepts as described.

Therefore, what is to be protected by way of Letters Patent are limitedonly by the scope of the following claims:
 1. A method of cleaning of aportion of a mold component, the portion of the mold component includinga passage configured, in use, to allow passage of fluid and to preventpassage of melt, the method comprising: entering the mold component intoa cleaning configuration, whereby a portion of the passage becomes partof a molding surface; performing a molding cycle to fill in at least theportion of the passage with molding material for incorporation andremoval of a residue therefrom.
 2. The method of claim 1, furthercomprising ejecting the molded article from the molding structure, themolded article comprising a molded appendix corresponding to the shapeof the at least a portion of the venting structure.
 3. The method ofclaim 1, further comprising controlling a predefined point for the meltfront stop.
 4. The method of claim 1, wherein said at least the portionof the passage comprises the portion that is, in use during standardmolding, is wetted by the gas.
 5. The method of claim 1, furthercomprising during said performing, increasing pressure between the meltand the residue.
 6. A method of operating a mold comprising: maintaininga neck ring in a standard molding configuration and executing at leastone molding cycle; actuating the neck ring into a vent cleaningconfiguration and executing at least one molding cycle in the ventcleaning configuration to remove residue from at least a primary ventarea of the neck ring.
 7. The method of claim 6, wherein said actuatingcomprises reducing tonnage.
 8. The method of claim 7, wherein saidreducing tonnage comprises reducing tonnage by between 10 and 15 percentbelow the injection pressure for the mold.
 9. The method of claim 6,wherein said actuating comprises controlling the width of the primaryvent area.
 10. The method of claim 6, wherein the neck ring comprising aventing structure that includes the primary vent area, wherein saidactuating comprises controlling the width of the primary vent area. 11.The method of claim 6, wherein said actuating comprises mechanicallycontrolling the separation between machine components.
 12. The method ofclaim 6, wherein the neck ring comprising a venting structure thatincludes the primary vent area, a secondary vent area and a pocketgroove in fluid communication with both the primary vent area and thesecondary vent area; and wherein said maintaining comprises: maintainingthe primary vent area in a dimension for (i) allowing the passage of theevacuated fluid from the molding cavity into the pocket groove and (ii)not allowing any substantial amount of the molding material for passingtherethrough; and maintaining the secondary vent area is dimensionedsuch that it prevents passage of any substantial amount of the moldingmaterial for passing therethrough.
 13. The method of claim 6, whereinthe neck ring comprising a venting structure that includes the primaryvent area, a secondary vent area and a pocket groove in fluidcommunication with both the primary vent area and the secondary ventarea; and wherein said maintaining comprises: maintaining the primaryvent area in a dimension that allows the molding material for passinginto it; and maintaining the secondary vent area in a dimension that isconfigured for (i) allowance of the passage of the evacuated fluid fromthe primary vent area and (ii) not allowing any substantial amount ofthe molding material for passing therethrough.
 14. The method of claim6, further comprising ejecting the molded article from the neck ring,the molded article comprising a molded appendix corresponding to theshape of the primary vent area.
 15. A method of operating a mold, themold comprising a first mold half and a second mold half, the first moldhalf and the second mold half defining a passage configured, in use, toallow passage of fluid and to prevent passage of melt, the methodcomprising: maintaining the mold in a standard molding configuration andexecuting at least one molding cycle; actuating the first mold half andthe second mold half into a cleaning configuration and executing atleast one molding cycle in the cleaning configuration to remove residuefrom at least a portion of the passage.
 16. A method of operating aninjection mold comprising: i. operating the mold in a first operationalconfiguration; ii. varying a mold shut height of the mold; iii.operating the mold in a second operational configuration.
 17. A methodas claimed in claim 16 wherein said mold comprises: (a) a first moldhalf; (b) a second mold half, said first and second mold halves beingsupported in movable spaced relationship to each other, said first andsecond mold halves being separated from each other by a mold shut heightwhen said mold is said first and second operational configurations (c) amold shut height adjustment apparatus operable to vary the mold shutheight.
 18. A method as claimed in claim 17 wherein said mold shutheight adjustment apparatus is integrated with at least one of saidfirst mold half and said second mold half.
 19. A method as claimed inclaim 16 wherein by operating said mold shut height adjustment apparatusthe mold shut height is varied to facilitate the reconfiguration of saidmold between said first operational configuration and said secondoperational configuration.
 20. A method as claimed in claim 16 whereinsaid first mold half comprises a core plate and said second mold halfcomprises a cavity plate.
 21. A method as claimed in claim 16 whereinsaid first operational configuration is associated with a first moldshut height S1 and said second operational configuration is associatedwith a second mold height S2 that is different than S1.